CODEWITHSUNDEEP
swiftsprite-kit
Astrum
Astrum

Reputation: 375

EXC_BAD_INSTRUCTION when spawning an object

So I'm trying to spawn a falling object in my game and i'm using an array to set all the possible xSpawn points and then I randomise through the array to get an x value but the problem is when It gets to this line in the code:

let SpawnPoint = UInt32(randomX)

It gives me the EXC_BAD_INSTRUCTION error and I can't seem to see why. I'm still new to swift so an explanation as to why it gives me an error at this point would be greatly cherished.

Full Code: 

func spawnFallingOjects() {

    let xSpawnOptions = [-50, -100, 0, 100, 150]

    let randomX = xSpawnOptions[Int(arc4random_uniform(UInt32(xSpawnOptions.count)))]


    let Bomb = SKSpriteNode(imageNamed: "YellowFrog")
    Bomb.zPosition = 900


    let SpawnPoint = UInt32(randomX)      

    Bomb.position = CGPoint(x: CGFloat(arc4random_uniform(SpawnPoint)), y: self.size.height)

    let action = SKAction.moveToY(-350, duration: 2.0)
    Bomb.runAction(SKAction.repeatActionForever(action))

    self.addChild(Bomb)

}

Upvotes: 0

Views: 35

Answers (1)

Crowman
Crowman

Reputation: 25908

Two out of five members of xSpawnOptions are negative numbers, which cannot be represented in an unsigned integer. So when you try to convert them to such with:

let SpawnPoint = UInt32(randomX)

it crashes as you'd expect.

It's not clear what you're trying to do with your random number generation, but one way or another you need to change the logic of it to account for this, perhaps by calculating a random number which is always positive, and then adding or subtracting an offset to it, for example:

let SpawnPoint: UInt32 = 50     

Bomb.position = CGPoint(x: CGFloat(Int(arc4random_uniform(SpawnPoint)) + randomX), y: self.size.height)

Upvotes: 1

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